<!-- 轮播图组件 -->

<script lang="ts" setup name="XtxCarousel">
import { BannerItem } from '@/types/data';
import { onBeforeUnmount, onMounted, ref } from 'vue';

//  接收父传的数据
// 定义 props
const { slides , autoPlay=true , duration =30000 } =  defineProps< {
  slides:BannerItem[]
  autoPlay?:boolean    //是否开启自动播放
  duration?:number
}>()


//  可以不使用还在实验阶段的 vite.config.ts 的语法
// const props =  defineProps<{
//   slides:BannerItem[]
//   autoPlay?:boolean  //是否开启自动播放
//   duration?:number
// }>()
// const { slides , autoPlay, duration } = toRefs(props)

// 当前图片
const active = ref(1)
// 点击右箭头换轮播图
const hNext = () =>{
  // console.log(active.value)
  // console.log(slides)
  active.value++
  if(active.value === slides.length){
    active.value = 0
  }
}
// 点击左箭头换轮播图
const hPrev = () =>{
  active.value--
  if(active.value < 0){
    active.value =slides.length -1
  }
}

// 如果开启了自动播放,则每隔 duration 去播放下一个 hNext()
onMounted(() =>{
  start()
})
onBeforeUnmount(()=>{
  stop()
})
let timer = -1
// 鼠标离开要继续播放
const start = () => {
  if(autoPlay) {
    timer = window.setInterval(() => {
      hNext()
    },duration)
}
}
 // 鼠标hover要暂停播放
const stop = () => {
  clearInterval(timer)
}

</script>

<template>
  <div class="xtx-carousel" @mouseleave="start" @mouseenter="stop">
    <ul class="carousel-body">
      <li 
      class="carousel-item " 
      :class="{fade:active === index}"
      v-for="(item,index) in slides" :key="item.id">
        <RouterLink :to="'/product/'+item.id">
          <img
            :src="item.imgUrl"
            alt=""
          />
        </RouterLink>
      </li>
    </ul>
    <!-- 箭头 -->
    <a @click="hPrev" href="javascript:;" class="carousel-btn prev"><i class="iconfont icon-angle-left"></i></a>
    <a @click="hNext" href="javascript:;" class="carousel-btn next"><i class="iconfont icon-angle-right"></i></a>
    <!-- 圆点 -->
    <div class="carousel-indicator">
      <!-- 鼠标经过圆点,变更轮播图 @mouseover="active = ind" -->
      <span 
      @mouseover="active = ind"
      v-for="(it,ind) in slides" :key="ind" 
      :class="{active:active===ind }"></span>
    </div>
  </div>
</template>

<style scoped lang="less">
.xtx-carousel {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;
  .carousel {
    &-body {
      width: 100%;
      height: 100%;
    }
    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;  // 不可见
      transition: opacity 0.5s linear;
      &.fade {
        opacity: 1; // 可见
        z-index: 1;
      }
      img {
        width: 100%;
        height: 100%;
      }
    }
    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;
      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;
        ~ span {
          margin-left: 12px;
        }
        &.active {
          background: #fff;
        }
      }
    }
    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;
      &.prev {
        left: 20px;
      }
      &.next {
        right: 20px;
      }
    }
  }
  &:hover {
    .carousel-btn {
      opacity: 1;
    }
  }
}
</style>